Trauma is the major cause of mortality in individuals under 45 years of age. Failure to rapidly control hemorrhage leads to inadequate organ perfusion (shock) and is the major cause of death in these trauma victims. Accordingly, portable, non-surgical, hemostasis devices that are practical and easy to implement, and provide for rapid hemostasis in the trauma environment, offer great healthcare benefit. High Intensity Focused Ultrasound (HIFU) is a modality for delivering large amounts of energy to a specific site in tissue, and has been demonstrated in a number of studies to successfully induce hemostasis. A high power, high frequency portable amplifier is a vital component in implementing HIFU as a practical device. Based on proprietary amplifier and transducer matching technology under development at Engineering Acoustics Inc. (EAI) for sonar applications, the objective of this Phase I effort is to design a battery-powered, compact amplifier to meet the HIFU requirements. EAI will work with the Center for Industrial and Medical Ultrasound (CIMU) at the University of Washington, who have developed and tested successful HIFU systems to establish the specifications and requirements. The long-term goal of this collaboration is to provide the hardware necessary to implement a portable HIFU hemostasis system for trauma care. PROPOSED COMMERCIAL APPLICATIONS: HIFU systems have application for treatment or advanced trauma in civilian and military casualty care. Image-guided HIFU devices that can produce transcutaneous acoustic hemostasis have potential for use in bloodless surgery, and HIFU devices are in clinical trials for tumor necrosis. An efficient amplifier in a portable HIFU system would greatly accelerate dissemination of HIFU technology for these applications, and other research purposes.